1. Field of the Invention
The invention relates to two station machining vises. More particularly, the invention relates to two station machining vises facilitating easy replacement of jaws, a highly stable body, guaranteed alignment of a central block, and an efficient drive system.
2. Description of the Prior Art
Two station machining vises are known in the art. These stations permit an individual to non-simultaneously mount two work pieces on a single vise during the machining process. These vises are generally provided with great versatility to enhance the performance of the vise by limiting the effort required to use and modify the vise.
For example, many vises are known which include replaceable jaws to permit modification of the vise jaws when the vise is to be used with different work pieces. Many of these vises employ a knuckle on the vise slide which receives the replaceable vise jaw. As shown in Applicant's prior U.S. Pat. No. 5,505,437, entitled "TWO STATION MACHINING VISE WITH REMOVABLE AND OFFSETTABLE JAWS", which is incorporated herein by reference, these knuckles include contoured surface which engages a pin mounted in the underside of the vise jaw.
While structures such as these provide secure attachment of the vise jaw to the knuckle, the incorporation of the pin with the vise jaw is expensive. When jaws are manufactured to engage a knuckle such as that disclosed in the '437 patent, the vise jaw must be drilled to include a hole through which the pin may be placed. Once the pin is properly secured within the vise jaw, the vise jaw is ready for use. This is an expensive and time consuming process that must be performed for each vise jaw to be used with a vise assembly employing the structure embodied in the '437 patent.
In addition, the main body of most two station machining vises is manufactured to include a recess into which the front and rear slides of the vise may be placed. Generally, the bodies are extruded with a central recess having only side walls, and the front and rear ends of the main body are left open. Unfortunately, these extruded main bodies do not stand up to the substantial stress placed on the vises, and ultimately the vises may bend out of alignment. When this occurs the vises is no longer useful, and the vise must be replaced. In addition, vises designed in this manner allow for vibrations while work pieces are being machined. The vibrations produce undesirable finishes on work pieces and excessive wear of the machining tools. This design also allows fluid and debris to enter the internal workings of the vise, causing it to fail or wear out earlier than anticipated.
It is often desirable to provided a two station vise in which the rear vise jaw does not move until the front vise jaw fully engages the work piece. This is generally accomplished by providing the rear slide with a braking assembly that resists the movement of the rear vise jaw until the front vise jaw fully engages the work piece. Many of these two station vises are also provided with offset assemblies that work with the brake assembly to create a initial predetermined offset of the rear jaw when a work piece is being removed therefrom.
Unfortunately, the braking assemblies and the offset assemblies employed by current two station vises employ many components to achieve their desired results. As a result, they are often cumbersome and very difficult to manufacture. Further, the many components employed in these braking assemblies and offset assemblies make them difficult to use, adjust and repair.
A need, therefore, exists for a two station vise that overcomes the shortcoming of the prior two station vises. The present invention provides such a two station vise.